Репозиторий Университета

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Background: Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is the major cause of viral persistence in patients with chronic HBV infection. Understanding the mechanisms underlying stability and persistence of HBV cccDNA in hepatocytes is critical for developing novel therapeutics and managing chronic hepatitis B. In this study, we observed an unexpected increase in HBV cccDNA levels upon suppression of transcription by de novo DNA methyltransferase DNMT3A and uncovered additional mechanisms potentially involved in HBV cccDNA maintenance. Methods: HBV-expressing cell lines were transfected with a DNMT3A-expressing plasmid. Real-time PCR and HBsAg assays were used to assess the HBV replication rate. Cell cycling was analyzed by fluorescent cell sorting. CRISPR/Cas9 was utilized to abrogate expression of APOBEC3A and APOBEC3B. Alterations in the expression of target genes were measured by real-time PCR. Results: Similar to previous studies, HBV replication induced DNMT3A expression, which in turn, led to reduced HBV transcription but elevated HBV cccDNA levels (4-to 6-fold increase). Increased levels of HBV cccDNA were not related to cell cycling, as DNMT3A accelerated proliferation of infected cells and could not contribute to HBV cccDNA expansion by arresting cells in a quiescent state. At the same time, DNMT3A suppressed transcription of innate immunity factors including cytidine deaminases APOBEC3A and APOBEC3B. CRISPR/Cas9-mediated silencing of APOBEC3A and APOBEC3B transcription had minor effects on HBV transcription, but significantly increased HBV cccDNA levels, similar to DNMT3A. In an attempt to further analyze the detrimental effects of HBV and DNMT3A on infected cells, we visualized γ-H2AX foci and demonstrated that HBV inflicts and DNMT3A aggravates DNA damage, possibly by downregulating DNA damage response factors. Additionally, suppression of HBV replication by DNMT3A may be related to reduced ATM/ATR expression. Conclusion: Formation and maintenance of HBV cccDNA pools may be partially suppressed by the baseline expression of host inhibitory factors including APOBEC3A and APOBEC3B. HBV inflicts DNA damage both directly and by inducing DNMT3A expression.

© 2019 The Author(s) Antiviral interferons (IFN-alpha/beta) are possibly responsible for the high tolerance of bats to zoonotic viruses. Previous studies focused on the IFN system of megabats (suborder Yinpterochiroptera). We present statistically robust RNA sequencing (RNA-seq) data on transcriptomes of cells from the “microbat” Myotis daubentonii (suborder Yangochiroptera) responding at 6 and 24 h to either an IFN-inducing virus or treatment with IFN. Our data reveal genes triggered only by virus, either in both humans and Myotis (CCL4, IFNL3, CH25H), or exclusively in Myotis (STEAP4). Myotis cells also express a series of conserved IFN-stimulated genes (ISGs) and an unusually high paralog number of the antiviral ISG BST2 (tetherin) but lack several ISGs that were described for megabats (EMC2, FILIP1, IL17RC, OTOGL, SLC24A1). Also, in contrast to megabats, we detected neither different IFN-alpha subtypes nor an unusually high baseline expression of IFNs. Thus, Yangochiroptera microbats, represented by Myotis, may possess an IFN system with distinctive features. Biological Sciences; Immunity; Omics; Transcriptomics

© 2017 Elsevier B.V. Background: A major role of the innate immunity in the defence of mucosal tissue is well established. However, a balance between the main components of the immunity such as toll-like receptors (TLRs) and defensins in the pathology of upper respiratory tract in children has not been addressed yet. Our aim was to investigate the gene expression of some TLRs as well as alpha and beta-defensins in children suffered from adenoid hyperthrophy in comparison with healthy children. Methods: Samples (nasal epithelium and adenoids) from patients with hypertrophic adenoids (n = 77) and control group (n = 33) were investigated. Quantification of HBD-1 and 2 mRNA, alpha-defensin-HNP1 and toll-like receptors (TLR) 2, 4 and 9 mRNA expression was performed by real-time polymerase chain reaction (PCR). The detection of TLR4 and TLR9 was performed by immunohistochemistry. Results: The main finding of the study is a dramatic up-regulation of TLR2 and TLR4 expression (but down-regulation of TLR9) along with a significant reduction in the expression of the defensins in children with adenoid hyperthrophy. Conclusion: The data suggest that one of the mechanisms of mucosal involvement in the pathogenesis of upper respiratory tract infection might by a disbalance between TLRs and defensins revealed in our study.

© 2018, Pediatria Ltd. All rights reserved. The article presents results of conjugated pneumococcal vaccine use in combination with basic therapy in 64 children with chronic compensated tonsillitis. The study showed that vaccination assists activation of T-lymphocytes subpopulation, increases sensitization to bacterial antigens, normalization of proinflammatory cytokines content, which is clinically manifested in a significant decrease in acute respiratory infections incidences and antibacterial therapy courses for 2 years after vaccination compared to patients receiving a traditional therapy course.

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered.

© Saint Petersburg Pasteur Institute. All rights reserved. Microfold cells (M cells) are specialized intestinal epithelial cells that initiate mucosal immune responses. These unique phagocytic epithelial cells are specialized for the transfer of a broad range of particulate antigens and microorganisms across the follicle-associated epithelium (FAE) into the gut-associated lymphoid tissue (GALT) by a process termed transcytosis. The molecular basis of antigen uptake by M cells has been gradually identified in the last decade. Active sampling of intestinal antigen initiates regulated immune responses that ensure intestinal homeostasis. The delivery of luminal substances across the intestinal epithelium to the immune system is a critical event in immune surveillance resulting in tolerance to dietary antigens and immunity to pathogens (e.g., bacteria, viruses, and parasites) and their toxins. Several specialized mechanisms transport luminal antigen across the gut epithelium. Discovery of M cell-specific receptors are of great interest, which could act as molecular tags for targeted delivery oral vaccine to M cells. Recent studies demonstrated that M cells utilize several receptors to recognize and transport specific luminal antigens. Vaccination through the mucosal immune system can induce effective systemic immune responses simultaneously with mucosal immunity. How this process is regulated is largely unknown. This review aims to show a new understanding of the factors that influence the development and function of M cells; to show the molecules expressed on M cells which appear to be used as immunosurveillance receptors to sample pathogenic microorganisms in the gut; to note how certain pathogens appear to exploit M cells to inject the host; and, finally, how this knowledge is used to specifically "target" antigens to M cells to attempt to improve the efficacy of mucosal vaccines. Recently, substantial progress has been made in our understanding of the factors that influence the development and function of M cells.

© Ruslania 2018. All rights reserved. The patients with odontogenic phlegmon of maxillofacial area suffer from immune depression at the surgical stage of treatment that can unfavorably affect their rehabilitation. The study analyzes possibility of application of medication Dalargin in complex treatment ofpatients during post-operation period. The experimental study established components of immune system affected by medication. Thereupon, Dalargin was applied in clinical practice oftreatment ofpatients with course ofdisease ofaverage severity. The study proved immunomodulatory characteristics of Dalargin effecting various fractions of sub-populations of lymphocytes and manifesting by way of decreasing of initially high indices and increasing of initially low indices that is of great importance during treatment ofpatients with odontogenic hormones, especially in case ofsevere course of disease.

© Saint Petersburg Pasteur Institute. All rights reserved. The aim of the present systematic literature review is to summarize data on the role of TLRs in maintaining homeostasis of the female genitals, in maintaining the physiological development of pregnancy, provision of anti-infective resistance in pregnant women with intrauterine infection. The review substantiates the importance of TLRs of female genitals as a necessary and determining factor in the reaction to various changes in the environment, and also responsible for changes in metabolic, structural, or energy, in the maintenance of anti-infective resistance and homeostasis. As universal regulators of vital activity of organism TLRs in conjunction with other receptors of innate immunity provide maintaining the general reactivity and anti-infective resistance at the physiological level. In physiologically developing pregnancy in a background of immunosuppression in response to pregnancy TLRs during contact with infectious and non-infectious pathogens stimulate the production of nonspecific adaptive immunity factors (defensins, cathelicidins, histatines, etc.), which together with the non-specific innate factors lysozyme, complement, properdin, etc. support anti-infective resistance of the female genitals at a high level at the beginning of the infectious process. Possible violations of the development of pregnancy may be accompanied by changes in the response of TLRs to infectious and non-infectious factors until hyper-reaction, excessive inflammation or apoptosis, which requires adequate management of pregnancy. Was established the significance of the influence of pathogens of infectious and noninfectious origin in intrauterine infection indirectly through TLRs in the homeostasis of the organism, on the formation of breaches in anti-infective resistance at the organism and community level the identification of new pathophysiological and immunological pathogenetic mechanisms of development of pathological processes. IUI is a penetration of microorganisms into the tissues of fetus and it's infection. The inhibition of the functional activity of TLRs is accompanied by the direct effect of the pathogen on the tissues, and during hyper-reaction of TLRs to pathogens revealed a pronounced inflammatory response in the fetus. The level of expression of TLRs correlates directly with the severity of the process that can be considered as early markers of infection. Depending on the nature of the pathogen an increased expression of one or the other TLRs is observed. Explained the lack of symptoms, the possibility of atypical manifestations, the asymptomatic course of infection.

Research objective was assessment of a possibility of primary diagnosis of viruses Epstein-Burr, a cytomegalovirus, a virus of herpes of the 6th type in oral liquid and also influences of herpes infection on development and the clinical course of precancer diseases of the oral mucosa and the red border of lips (RBL). Profound clinic-immunological examination is conducted to 60 patients: the first group are have made 20 patients with an erosive and ulcer form of the lichen planus, the second - 20 people with an erosive form of a leukoplakia, a third - 20 people without diseases of the oral mucosa. As a result of work detection herpes infection is revealed high (90%). The combined infection with a virus Epstein-Burr and a virus of herpes of the 6th type was observed more than at a half of patients. The imbalance of factors of local immunity of the oral cavity in the form of increase in the IgG profile, decrease in concentration of IGA, lysozyme, and increase in an indicator of Ksb three times in comparison with norm and also substantial increase of level of pro-inflammatory cytokin IL 1β and FNO-α is found in patients with precancer diseases of the oral mucosa. Characteristic clinical feature of the precancer diseases associated with latent herpes infection is the long, recidivous current, persistent to traditional therapy. The research of oral liquid and blood on herpes viruses and consultation of the infectiologist is recommended to all patients with precancer diseases.

© 2018 Dynasty Publishing House. All rights reserved. The objective: The purpose of the study is to establish the role of infection with herpes simplex viruses type I and II in the pathogenesis of urogenital infection in pregnant women. Patients and methods: 89 patients of I, II trimester gestation, aged 18 to 35 years (average age of 27.5 ± 5.6 years) were examined. The design of the research and the methodology of verification of the UGI pathogens of pregnant women are presented in previously published materials. The establishment of character of pregnancy course (urgent delivery, premature birth, termination of pregnancy and mis-carriage), the presence or absence of infection and/or clinical manifestations of infectious and inflam-matory diseases, as well as evaluating the gene expression of TLR-2, TLR-3, TLR-4, TLR-8 (in relative units - RU) was conducted according to manuals. Results: It is established, that in UGI in pregnant combined viral-bacterial infection is registered. Viral component of UGI pathogens in pregnant women is presented by the association of viruses from the Herpesviridae family - herpes simplex viruses, Cytomega-lovirus, Epstein-Bar virus. Against the background of polyfactorial mechanisms of the pathogenesis of abortion, extra maximum activation of gene expression of TLR (22-23 RU or more) additional external factors, for example, infections can be an aggravating pathogenetic factor of miscarriage. Reduced expression of genes of TLR2, TLR4, TLR3 and TLR8 in the mucous membrane of the cervical canal in UGI of pregnant women in infection with herpes simplex virus due to the oppressive effect of pregnancy on the reaction of TLR, combined with the immunodepressive effect of the virus itself. With the violation of cellular part of immuno-logical reactivity of the body under the influence of adverse endogenous and exogenous factors on the process of pregnancy is activated the infectious process caused by the bacte-rial-viral pathogens association, which is accompanied by hyper reaction and increased reaction from the expression of genes of TLR, determines the pathological development of pregnancy. It is established that in the UGI of pregnant gene expression levels of TLR2-21.2 and above, TLR4-23.0 and above, TLR8 - 26.0 and above (the level of gene expression of TLR8 above 28 is the predictor of the onset of abortion and miscarriage) testify to the acute infectious process with the clinical manifestations of the UGI, and also indicates the possible interruption of pregnancy and miscarriage; levels of gene expression of TLR2 below 21.2, TLR4 below 23.0, TLR8 below 26.0, in-dicated a decrease in the severity of the infectious process and its chronicity, as well as the possibility of direct microbial damage to the tissues of UGT, placenta, and fetus. Conclusion: Verified in preg-nant women in 61% of cases clinical manifestations of the infectious process are necessarily associated with the verification of the association of herpes simplex viruses I and II type - triggers of infectious process deterioration, determining the prognosis and outcome of the development of the UGI in preg-nant.

© 2018 Media Sphera Publishing Group. All rights reserved. The outcome of diseases accompanied or caused by mucostasis depends both on the restoration of drainage function of the airways and on the effectiveness of immune mechanisms against pathogens. N-acetylcysteine (NAC) is widely used as mucolytic and antioxidant remedy in clinical practice. In this regard, the data of the scientific literature on the direct and indirect effects of NAC on the mucosal immunity of the respiratory tract have been reviewed. NAC possesses pleiotropic immunomodulating properties, most of which contribute to the regression of clinical manifestations of acute and chronic inflammatory diseases of the respiratory tract. Biological and pharmacological effects of NAC include improvement in rheological properties of mucus, reduction of excess mucin production, restoration of mucociliary clearance and production of sIgA, suppression of excess production of IgE and IgG4, destruction of biofilms and inhibition of their formation, suppression of adhesion of pathogenic bacteria to epithelial cells, antioxidant activity, regulation of the production of pro-inflammatory and profibrotic cytokines. There was no convincing evidence that NAC is able to suppress any component of mucosal immunity. For final conclusions on this subject, further research are required.

© 2018, SPb RAACI. The aim of this work was to study features of gene expression TLR2, TLR4, and TLR9 in the course of acute respiratory infection, depending on the time elapsing since the contamination, and dose of infection. The studies of in vivo models of acute respiratory infections caused by Gram-negative Klebsiella pneumoniae showed that, at infection dose of 104 CFU/ml, the TLR4 gene expression levels in epithelium of upper respiratory tract at 1, 3, 10 days were increased 30 times and more, complete elimination of the pathogen was observed at 3 days. At the dose of infection of 107 CFU/ml, persistence of the pathogen in upper respiratory tract was observed within a few days, accompanied by a significant increase in the level of TLR9 expression in epithelium of upper respiratory tract, and TLR4 levels in the lungs 1 day after infection, in parallel to elimination of the pathogen from the lower respiratory tract. Thus, the characteristic features of TLR4 and TLR9 gene expression in the upper respiratory tract may be considered a potential diagnostic and prognostic factors in evaluation of the course of acute respiratory infections caused by Klebsiella pneumoniae.

© Saint Petersburg Pasteur Institute. All rights reserved. The review is devoted to the analysis of pertussis incidence of children in the age group of 5-7, as well as strategies of DTP immunization with the help of the drugs in foreign countries. Mass vaccination against pertussis began in the middle of the 20th century, which contributed to a reduction in incidence and mortality rate from this infection. However, in the last decade, there has been an opposite tendency of increasing incidence of patients among children under school age, school age and adults. Atypical forms of the disease and complications due to ARVI, respiratory mycoplasmosis and cytomegalovirus infections are described in the review. Various strategies for the use of whole-cell and acellular pertussis vaccines as part of DTP drugs are described, as well as the epidemiological effect of introducing an additional booster dose of vaccine to children under school age. The expediency of revaccination of children aged 6-7 in Russia is argued, which can help to reduce the overall incidence of pertussis. The research materials related to the study of the properties of acellular anti-pertussis vaccine, such as immunogenicity and safety in comparison with whole-cell vaccine, are analyzed. The main drugs and their composition, which are used to vaccinate children against pertussis, are described in the review. It is assumed, that the increase in the incidence among children and teenagers, with the appearance of atypical forms of pertussis, is associated with a number of factors, such as the spread of new genotypes of Bordetella pertussis bacterium, emerged from mutations, as well as short duration of immunity after vaccination with acellular drugs, in comparison with whole-cell, and the use of more modern methods of detecting the pathogen. The mechanisms of the immune response due to different types of pertussis vaccines are also reviewed. It is concluded, that revaccination of children aged 6-7 with an additional fifth dose of an acellular vaccine against pertussis, as part of the DTaP instead of the Td drug, which is regulated in the National Calendar of preventive vaccinations, will have a favorable effect on the epidemic situation with pertussis infection in Russia.

© 2018 Dynasty Publishing House. All rights reserved. The systematic review provides a justification for the value of innate immunity as an initial, necessary and determinant stage in the development of adaptive immunity. The participation of TLRs as a leading component of PRRs-system in maintaining natural congenital anti-infection resistance and homeostasis of the organism, in launching and dynamics of development of adaptive immunity to pathogens of infectious and non-infectious genesis was studied in detail. The importance of the influence of these pathogens on the homeostasis of the organism, on the formation of disturbances in anti-infective resistance at the organism and local levels, revealing new pathophysiological and immunological pathogenetic mechanisms of the development of these pathological processes is established. The colossal gap between fundamental studies of the biology and morphology of microorganisms and clinical studies of the diseases they cause is shortening. In an accessible form, explanations are provided for the absence of symptoms, the possibility of atypical manifestations, and the asymptomatic course of infection. There are new wide opportunities to improve and enhance the information content and personalization methods of diagnosis, treatment and prevention, as well as the creation of pharmaceuticals that act detrimental to all forms of cycle of development of pathogens, and new immunomodulatory drugs for the most effective treatment and prevention of diseases.

© 2018, SPb RAACI. The theory of polyetiological tumorigenesis is one of the most important theories of carcinogenesis. A great place in this theory is given to the role of inflammatory component, which is implemented via the factors of innate immunity. I.e., toll-like receptors (TLRs), chemokines and their receptors are related to innate immunity. Activation of TLRs may lead to regress or progression of cancer process. It is known that TLR3, TLR5, TLR7, TLR9 have the greatest anti-Tumor effect due to the dendritic cells (DCs)-mediated activation of type I T helpers, activation of M1-Type macrophages and Treg inhibition. Stimulation of TLR2 and TLR4 exerts an activating effect upon the tumor, by the MyD88 hyperactivation and secretion of IL-6 and TNFα, but exact mechanisms are not fully understood. In addition to TLRs, chemokines and their receptors have a great influence on the cancer development. It is shown that CCL2, CCL4, CCL17, CCL22 and CXCL12, which are secreted by cancer microenviroment, activate chemotaxis of tumor cells. It is also known that the chemokines activate CXCR4 and CCR7 (expressed by tumor cells) thus leading to metastasis. It is shown that there is an association between some gene polymorphisms of TLRs', chemokines and their receptors, and development of cancer. Thus, we may conclude that the role of TLRs and chemokines is important in oncogenesis. Further study of innate immunity factors influencing tumorigenesis are important for finding new approaches to cancer therapy and new potential vaccines against cancer.

© 2018 Medical Education. All Rights Reserved. The aims of the study were to examine age-related features of immune response to measles virus in staff of a large city hospital and to define groups at risk for measles outbreaks. Methods. The study involved 1,855 staff members of a large city hospital aged ≥ 19 years old who had documented vaccination against measles or a history of measles. The participants were divided into age groups with 5-year intervals starting from 19 years of age; there were 11 groups in total. The immune response to measles virus was measured in sera by ELISA using Vector-Best IgG-Kor test system (Russia). Results. Young employers of 19 to 23 years of age were most susceptible to measles; protective antibody level was not detected in 38.5% of them. They were followed by young-to-middle-aged workers (24 to 48 years old) who were negative for anti-measles antibodies or had non-protective level of antibodies in 16.7% to 27.5%. The anti-measles antibody level was low (42.3 % to 60.0 %) in employers of 19 to 43 years of age and gradually increased to 46.3% – 92.2% in the group of 44 to 68 years old. Conclusion. Herd immunity against measles in employers of a large city hospital did not meet requirements for successful infection control which implicates ≤ 7% of seronegative individuals. This means that measles outbreak could occur at any time because the proportion of seronegative individuals (11.5%) twice exceeded the cut-off value; the antibody level was controversial in 3.2% of individuals. Therefore, monitoring anti-measles antibody level in hospital staff is necessary to detect groups at risk who should be vaccinated against measles.

© 2018 Park-media, Ltd.  Common marmosets are small New World primates that have been increasingly used in biomedical research. This report presents efficient protocols for assessment of the parameters of adaptive cell-mediated immunity in common marmosets, including the major subpopulations of lymphocytes and main markers of T- and B-cell maturation and activation using flow cytometry with a multicolor panel of fluorescently labelled antibodies. Blood samples from eight common marmosets were stained with fluorescently labeled monoclonal antibodies against their population markers (CD45, CD3, CD20, CD4, CD8) and lymphocyte maturation and activation markers (CD69, CD62L, CD45RO, CD107a and CD27) and analyzed by flow cytometry. Within the CD45 + population, 22.7±5.5% cells were CD3 - CD20 + and 67.6±6.3% were CD3 + CD20 - . The CD3 + subpopulation included 55.7±5.5% CD3 + CD4 + CD8 - and 34.3±3.7% CD3 + CD4 - CD8 + cells. Activation and maturation markers were expressed in the following lymphocyte proportions: CD62L on 54.0±10.7% of CD3 + CD4 + cells and 74.4±12.1% of CD3 + CD8 + cells; CD69 on 2.7±1.2% of CD3 + CD4 + cells and 1.2±0.5% of CD3 + CD8 + cells; CD45RO on 1.6±0.6% of CD3 + CD4 + cells and 1.8±0.7% of CD3 + CD8 + cells; CD107a on 0.7±0.5% of CD3 + CD4 + cells and 0.5±0.3% of CD3 + CD8 + cells; CD27 on 94.6±2.1% of CD3 + cells and 8.9±3.9% CD20 + cells. Female and male subjects differed in the percentage of CD3 + CD4 + CD45RO + cells (1.9±0.5 in females vs 1.1±0.2 in males; p < 0.05). The percentage of CD20 + CD27 + cells was found to highly correlate with animals' age (r = 0.923, p < 0.005). The basal parameters of adaptive cell-mediated immunity in naïve healthy marmosets without markers of systemic immune activation were obtained. These parameters and the described procedures are crucial in documenting the changes induced in common marmosets by prophylactic and therapeutic immune interventions.

The review is summarizing for the first time the results of original research and literature data revealing the conditions of opportunistic microflora (OM) pathogenicity and virulence formation in the dynamics of the infectious process, as well as maintenance and formation of gene pools in host cells and microorganisms. It is established, that formation or loss of pathogenic and virulent properties of microorganisms in the body happens under the influence of its external environment, its overall physiological and immunological reactivity, mucosal immunity, as well as with the direct participation of horizontal gene transfer. Newly created microbial pathogens cause infectious-inflammatory diseases. However, acquired pathogenicity factors are lost after recovery. Plasticity of gene pools of the macroorganism and microorganisms allows owners of gene pools to respond adequately to changes in the external and internal body environment, improve and enhance overall and immunological reactivity of the macroorganism in ontogenesis, generate optimal for specific situations symbiotic or antagonistic relationships between them taking into account newly acquired or lost pathogenicity and virulence factors and form new phenotypic or genetic properties of microorganisms. Horizontal genetic transfer is the process of moving the genetic information which is possible between prokaryotic and eukaryotic cells both ways, as well as within a single cell.

Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered. View Full-Text

The review is summarizing for the first time the results of original research and literature data revealing the conditions of opportunistic microflora (OM) pathogenicity and virulence formation in the dynamics of the infectious process, as well as maintenance and formation of gene pools in host cells and microorganisms. It is established, that formation or loss of pathogenic and virulent properties of microorganisms in the body happens under the influence of its external environment, its overall physiological and immunological reactivity, mucosal immunity, as well as with the direct participation of horizontal gene transfer. Newly created microbial pathogens cause infectious-inflammatory diseases. However, acquired pathogenicity factors are lost after recovery. Plasticity of gene pools of the macroorganism and microorganisms allows owners of gene pools to respond adequately to changes in the external and internal body environment, improve and enhance overall and immunological reactivity of the macroorganism in ontogenesis, generate optimal for specific situations symbiotic or antagonistic relationships between them taking into account newly acquired or lost pathogenicity and virulence factors and form new phenotypic or genetic properties of microorganisms. Horizontal genetic transfer is the process of moving the genetic information which is possible between prokaryotic and eukaryotic cells both ways, as well as within a single cell.